You need to create a Stored Process in SAS Management Console, and assign it to use the Stored Process Server (not Workspace Server). Ensure it has the 'streaming output' checkbox selected.
The SAS code behind this Stored Process should then send the output (that you wish to receive from your python program) to the _webout fileref, eg:
data _null_;
file _webout;
put 'Hello python!';
run;
The %stpbegin
and %stpend
macros should NOT be used.
To reference the Stored Process just call the URL with your Stored Process name & path in the _program parameter, as follows:
http://[yourMachineName]:8080/SASStoredProcess/do?_PROGRAM=/Your/MetadataPath/YourSTPName